Following our tracks

The term “carbon footprint” refers to the size of a person, building, organization or event’s impact upon the earth, as measured by the greenhouse gases that it generates.

Frank Rukavina, sustainability director of National Renewable Energy Labs in Golden, points out that a carbon footprint calculation also measures greenhouse gases that are not carbon.

Sulfur hexafluoride for instance, has a 25-times greater greenhouse effect than the same amount of carbon dioxide.

“Even water acts as a greenhouse gas,” Rukavina said. “But when we look at GHG, we convert them all to a carbon equivalent.”

That is because carbon dioxide is the most abundant greenhouse gas. It stays in the atmosphere for a long time, and it is the one directly pumped into the atmosphere by smoke stacks and exhaust pipes.

The average “footprint” for a home in Lakewood is about 48.5 tons of carbon dioxide a year.

”It’s just not prudent to be doing this dumping of carbon into the atmosphere. It’s slowly heating up the planet and intensifying weather,” said Steve Stevens, a Golden resident, antique bicycle collector and conservation activist.

The vast majority of climate scientists agree that human activity is pumping enough greenhouse gas into the atmosphere that the world is heating up at a record pace.

Big feet

Measuring the carbon footprint of any given thing is difficult.

For a household, Rukavina says the measurement has to include three levels of GHG production:

• Scope one — Direct carbon put into the air by the car you drive, or your fireplace chimney;

• Scope two — Indirect carbon, notably the coal-fired power plant that provides the electricity for your home;

• Scope three — Associated household expenses like the carbon cost of the goods and services a family uses, and the treating of its wastewater.

The typical Jefferson County resident’s biggest single carbon-producing activity is driving, accounting for 10 tons of CO2 a year. As a category, however, home costs (construction, water, natural gas, electricity) are a bigger lump of carbon.

For the last few years, Stevens has turned his 1970s-era home into a showcase for sustainability.

He added inches of insulation to all exterior walls, installed solar panels capable of producing more than enough electricity for his home and electric car, and expanded the south face of his home to create a “catch it and keep it” passive solar heating system, which reduced his heating costs by 95 percent.

All told, Stevens estimates his household has a negative carbon impact.

Though he saves more than a thousand dollars a year on utility costs, Stevens said he chooses to focus on the moral and environmental reasons for reducing his carbon footprint.

”Carbon dioxide is invisible, so people don’t really pay attention to it. But oil and gas companies are treating the sky as a sewer,” Stevens said.

Drop a shoe size

The good news about carbon footprints are that small changes can have big effects, and often mean cost savings as well.

Many of these calculators include carbon-reducing recommendations. Buying a more fuel-efficient car costs a lot at first, but means 1.7 tons less carbon a year and hundreds of dollars of ongoing savings.

Eating a healthier “low carbon” diet — less meat and dairy and more fruit, vegetables, and cereal — can save carbon, money, and the waistline.

Home improvement projects can reduce, or in Stevens’ case, even reverse carbon impacts.

There are tools available for improving homes.

The NREL website www.nrel.gov features a map that shows the best regions for collecting solar or wind power.

Most electric utility companies, including Xcel Energy, offer cash rebates to home owners who have energy audits done.

The audits can identify spots of wasted energy.

Angelo Vialtando, an Xcel-certified energy auditor from Westminster, said that contracting companies like his own (AFV Inc./Extreme Energy Solutions) can provide a cost-benefit list of potential home improvement projects for homeowners to improve their energy efficiency.

”If you’re utility bills are high, or if you’re uncomfortable, too hot or too cold and feel like there’s a draft, there probably is, and you should get an audit,” Vialtando said.